import java.util.Stack;

class MinStack {
    public Stack<Integer> stack;
    public Stack<Integer> minStack;

    public MinStack() {
        stack=new Stack<>();
        minStack=new Stack<>();
    }
    
    public void push(int val) {
        stack.push(val);
        if(minStack.empty()){
            minStack.push(val);
        }else{
            Integer peekVal=minStack.peek();
            if(val<=peekVal){
                minStack.push(val);
            }
        }
    }
    
    public void pop() {
        if (stack.empty()) {
            return;
        }
        int popVal=stack.pop();
        if(popVal==minStack.peek()){
            minStack.pop();
        }

    }
    
    public int top() {
        if(stack.empty()){
            return -1;
        }
        return stack.peek();
    }
    
    public int getMin() {
        if(minStack.empty()){
            return -1;
        }
        return minStack.peek();
    }
}